Knitting machine

ABSTRACT

A knitting machine having a knitting needle bed or drum rotatably driven and carrying a plurality of knitting needles circumferentially spaced thereon actuated to knitting positions by respective jacks, selector levers and moving means. A selector system selectively selects individually which needles are to be disengaged from the moving means and disengages them individually from the moving means so that when disengaged they remain inactive on the needle bed. A slider reciprocably driven parallel to the axis of the needle bed by a sinusoidal cam on the needle bed mounts a plurality of selector arms that have their pivots on the slider reciprocated to two terminal positions of the slider. Two stationary abutments for each selector arm at one terminal posiof the slider function as fulcrums for each selector arm at opposite ends thereof. One of the abutments is an electromagnet. The individual selector arms are attached or biased to the other stationary abutment by individual springs or permanent magnets. The electromagnets are spaced from the pivots of the selector arms such that the selector arms have a greater lever arm length when fulcrumed on the corresponding electromagnet. The individual electromagnets are energized in accordance with a predetermined program or desired pattern so that in dependence upon the energization of its corresponding electromagnet selector arm will either pivot on the other abutment or on the corresponding electromagnet as the slider moves to its opposite terminal position. If the corresponding electromagnet is energized the selector arm has a lever arm length effective to be in the path of a selector lever associated with a corresponding needle controlled by the selector arm to disengage it from the moving means so that the needle is rendered inactive. The moving means has means that automatically cooperate with the selector lever to re-engage the individual needles with the moving means after each disengagement.

United States Patent [191 Ringrose 1 Sept. 30, 1975 l l KNITTING MACHINE [75] Inventor: Anthony S. Ringrose, Geneva.

Switzerland [73] Assignee: Battelle Memorial Institute, Geneva.

Switzerland [22] Filed: Feb. 26, 1974 [2 l] Appl. No.: 445,863

lrilmlry E.vuminer--Louis K. Rimrodt Attorney, Agent, or FirmRobert E. Burns; Emmanuel J. Lobato; Bruce L. Adams [57} ABSTRACT A knitting machine having a knitting needle bed or drum rotatably driven and carrying a plurality of knitting needles circumferentially spaced thereon actuated to knitting positions by respective jacks, selector levers and moving means. A selector system selectively selects individually which needles are to be disengaged from the moving means and disengages them individually trom the moving means so that when disengaged they remain inactive on the needle bed. A slider reciprocably driven parallel to the axis of the needle bed by a sinusoidal cam on the needle bed mounts a plurality of selector arms that have their pivots on the slider reeiprocated to two terminal positions of the slider. Two stationary abutments for each selector arm at one terminal position of the slider function as fulcrums for each selector arm at opposite ends thereof. One of the abutments is an electromagnet. The individual selector arms are attached or biased to the other stationary abutment by individual springs or permanent magnets. The electromagnets are spaced from the pivots of the selector arms such that the selector arms have a greater lever arm length when fulcrumed on the corresponding electromagnet. The individual electromagnets are energized in accordance with a predetermined program or desired pattern so that in dependence upon the energization of its corresponding electromagnct selector arm will either pivot on the other abutment or on the corresponding electromagnet as the slider moves to its opposite terminal position. If the corresponding electromagnet is energized the selector arm has a lever arm length effective to be in the path of a selector lever associated with a corresponding needle controlled by the selector arm to disengage it from the moving means so that the needle is rendered inactive. The moving means has means that automatically cooperate with the selector lever to reengage the individual needles with the moving means after each disengagement.

7 Claims, 7 Drawing Figures U.S. Patent Sept. 30,1975 Sheet 1 of 3 3,908,403

f ZW ZM z I l I I v we qg 2 1 v a US. Patent Spt. 30,1975 Sheet3 0f3 3,908,403

KNITTING MACHINE BACKGROUND OF THE INVENTION This invention relates generally to knitting machines and more particularly to a knitting needle selector system therefore.

Many kinds of needle selector mechanisms are know for jacquard knitting machines, based on the principle of making each knitting needle rise by means ofa jack which is moved into its operative position by an electromechanically controlled selector programmed in ac cordance with the required knitting pattern. Some of these selector mechanisms use an electromagnet adapted to selectively move a selector biased by a return or restoration spring The main disadvantage of this system is that the electromagnet must overcome the opposing restoration force of the spring, and to ensure adequate reliability of operation the electromagnet must be fairly powerful and therefore relatively large.

In endeavors to obviate this disadvantage, two relatively small electromagnets have been used for each selector so as to do away with the return spring. The polarity of the electromagnets is reversed to move the selector between the electromagnets. Since a large number of selectors is needed for every machine, doubling the number of electromagnets is a considerable disadvantage, interalia as regards cost.

Another idea is to use the loom drive mechanism to set the selector; to this end, each jack is controlled by two opposing springs a selector spring and a cancelling or restoration spring A stationary cam is disposed in the path of the selector spring to move the same on to a stationary electromagnet which releasably retains the spring selectively. The spring, unless retained by the electromagnet, is pressed centripetally by a second cam at a pressure greater than that of the restoration spring, so that the selector spring pushes the jack into the selection position.

Unfortunately, this system has many disadvantages. Two springs per needle are needed. To move the jack into the selection position the selector spring must overcome the pressure of the cancelling spring. Multilevel selection is impossible. There is a relative movement between the selector spring and the electromagnet when the same retains the spring, so that the same experiences a tangential force.

SUMMARY OF THE INVENTION It is an object of the invention at least to reduce the disadvantages of the systems hereinbeforere referred This invention accordingly relates to a knitting machine having a frame carrying a moving support having a number of needles adapted to take up or assume two positions an operative position and an inoperative position a system for driving the support, means for individually moving the needles between their two positions, and a system for selecting such means. According to the invention, the selector system comprises:

at least one moving selector arm having at one end a cam disposed near the support and adapted to act selectively on the needle-moving means;

a slider which is substantially perpendicular to the selector arm and which is pivoted thereto and which is disposed between guides rigidly secured to the frame;

a cam which has a substantially sinusoidal profile and which is solid in movement with the system for driving the support and with the slider to reciprocate the same between two positions, the cycle of such reciprocation corresponding to the consecutive passage past a fixed point of two needles controlled by the selector arm;

two abutments which are simultaneously adjacent the selector arm in one of its two end positions defined by the slider, and

means for continuously applying to the arm a first and predetermined force towards one of the abutments when the same makes contact with the selector arm, and means for selectively applying to the selector arm a second force which is greater than the first force and which is operative towards the other of the abutments when the arm contacts such other abutment, so that the selector arm pivots while bearing on one or other of the abutments according as the second force is or is not applied, causing the cam which is rigidly connected to the selector arm to make a movement proportional to the length of the lever arm chosen.

This solution of the problem is very simple and ensures high selector reliability because the selector arm moves solidly with the loom drive mechanism to give completely synchronous operation. Since the slider drives the selector, the same is solid in movement with the needle bed driven by the loom drive. Selection is simply a matter of changing the fulcrum of the selector arm. Of course, the slider can carry a number of selector arms for multilevel selection. Also, as will be seen in the following description, the selector system can operate without any spring.

BRIEF DESCRIPTION OF THE DRAWINGS An embodiment of a knitting machine according to this invention is shown diagrammatically and by way of example in the accompanying drawings wherein:

FIG. 1 is a fragmentary view, in a section line along a diameter of a selector system according to the invention;

FIGS. 2 to 4 are diagrams showing three phases in the operation of a selector of the selector system of FIG. 1;

FIGS. 2a and 3a are detailed views showing variants of FIGS. 2 and 3 respectively, and

FIG. 5 is a detailed view on the taken section line VV of FIG. 1.

DESCRIPTION OF PREFERRED EMBODIMENTS Referring to FIG. 1, a knitting machine according to the invention comprises a needle bed I mounted in a frame 2 for rotation around a vertical axis (not shown). The bed 1 is formed with a number of vertical tricks 3 in its outside lateral surface, only one of the tricks is visible in FIG. 1. Three elements are retained by friction in trick 3 a selector lever 4 articulated at its bottom end in a semi-circular groove 5 at the base of trick 3, a jack 6 and a knitting needle 7. The jack 6 is engaged at the bottom between jaws 8 and 9 of a resilient gripper manufactured together or integral with the top part of the lever 4. The top end of thejack 6 has a semicircular head 6a which is engaged in a matching recess or socket in the base or bottom of the needle 7. The

jack 6 and the needle 7 have a butt 6b 7b respectively disposed opposite cams 10, 11 formed in the frame 2. The lifting cam 10 controls needle ascent and the lowering cam 11 controls needle descent. The selector lever 4 has a bent arm or elbow 4a forming a step engagable with a cam 12 rigidly secured to the frame 2. The selector lever 4 also has a butt 4b disposed to project from trick 3 when the selector lever 4 pivots or tilts centrifugally.

A driven circular cam 13 is disposed in the thickness of an annular part la which projects radially around the needle bed bottom end. Engaging in the cam 13, which is of sinusoidal contour, is a roller 14 which projects laterally from the base of a vertical slider 15 extending through a casing 16 in which a tenlevel selector mechanism is disposed. That part of the slider 15 which is inside the casing 16 carries ten pins 17 which extend laterally of the slider longitudinal axis and to which ten selector arms 18 are pivotally connected in their central parts. The arms 18 each terminate in a cam 18a at the end near the needle bed 1 and at their other ends are articulated to a soft-iron member 18b.

Two abutments 19, 20 are disposed axially spaced on the same side of each arm 18 and on either side of the slider 15 and are secured to the casing 16 in a position such that they are simultaneously in contact with their respective selector arm 18 when the slider 15 has been moved into its top position by cam 13 (FIG. 2). A permanent magnet 21 is disposed beside each abutment 19 between the same and the slider 15. The other abutment 20 is embodied by one of the pole faces of an electromagnet 22. Each electromagnet 22 is connected, for energizing thereof, to a programmed control station PS synchronized with the angular position of the needle bed 1.

Consequently, since all the arms 18 are solid in movement with the slider 15, the arms 18 move continuously in vertical reciprocation for as long as the machine is in operation. Due to the presence of the permanent magnets 21, beside the abutments 19, while the respective electromagnet 22 stays inoperative every arm 18 is kept in contact with its respective abutment 19. Each arm 18 therefore reciprocates around abutment 19, leading to an imperceptible oscillation of the arm cam part 18a around the abutment 19 and to a greater oscillation of the other end of the arm 18. FIGS. 2 and 4 show these two end positions. If, on the ohter hand, the electromagnet 22 is energized when arm 18 is in the position shown in FIG. 2, the soft-iron member 18b pivoted to the rear end of arm 18 remains in engagement with the pole face 20 since the attraction of the electromagnet is greater than the attraction of the permanent magnet 21; consequently, when the slider 15 descends the arm 18 moves into the position shown in FIG. 3 i.e., its cam 18a is in the path of the butt 4b of its respective selector lever 4.

The shape of the cam 18a, which is shown in plan in FIG. 5, is such that the arm 18 pushes the selector lever butt 4b into the trick 3, so that the selector lever 4 pivots around its bottom end which is engaged in pivot groove 5. During this pivoting movement the selector lever 4 moves the jack 6 towards the base of the trick 3 and causes the jack top end 611 to pivot in the recess or socket in the bottom of the needle 7. This pivoting of the jack 6 causes its butt 6b to disengage from the lifting cam 10. With the jack 6 and the lifting cam 10 in this disengaged position, the jack 6 stays at the same level as shown in FIG. 1 so that the needle 7 is not lifted and does not knit,

When a selector lever 4 arrives upstream of the selector mechanism with its butt 4b pressed into the trick 3 by a selector arm, the function of the cam 12 is to pivot the selector lever 4 in the opposite direction to bring its butt 4b out of the trick 3. Consequently, the cam 12 returns all of the selector levers 4 to the selection position and they are pushed back into the trick 3 only if their respective needles are required not to knit.

If the electromagnet 22 is not energized, the selector arm 18 experiences an oscillating motion whose end positions are shown in FIGS. 2 and 4, so that the selector arm 18a remains above the path of the butt 4b of its respective selector lever 4. The same therefore stays in the position determined by cam 12, and so the jack butt 6b stays engaged in the lifting cam 10 which lifts the needles 7 into the operative position, whereas cam 11 then returns the needles to the position shown in FIG. 1.

Since the ten selector arms 18 are rigidly secured to a common slider 15 but are required to cooperate with a system of ten needles disposed in ten consecutive tricks 3 of bed 1, the ten selector arm cams 18a of a single selector mechanism must be offset from one another by the amount of the angular separation between any two consecutive needles, as shown in FIG. 5.

FIGS. 2a and 3a show a variant for the selector arms 18, the permanent magnets 21 are replaced by springs 23 which develop a pull less than the attractive force of the electromagnet 22. The springs 23 have exactly the same function as the permanent magnets 21 i.e., to maintain the selector arms 18 in engagement with the respective abutments 19 while the respective electromagnets 22 are not energized.

Referring again to FIG. 1, when an arm 18 is in its limit pivoting position around abutment 20 the arm 18 is nearer the permanent magnet which is below it than the permanent magnet which is above it and which nor mally serves to retain it against abutment 18 when the electromagnet is not energized. Consequently, the arm when in its end pivoting position around abutment 20 has applied to it by the permanent magnet below the arm a force which is opposite to and greater than the force of the electromagnet 21 above the same arm. This is an important feature in the event of an interruption in the machines power supply, since the selector arms 18 are retained in the position which they occupy at the time of stoppage, so that the machine can restart without defects occurring in the knit.

The selection mechanism described is very simple and reliable. It is a means of obviating return springs, which are always delicate items, for even when spring 23 are used they do not act as a return element. The selector arm is rigid and is solid in movement with the needle bed 1 in both the selection and miss positions. The electromagnet works only by attraction and so needs to provide only a relative reduced force. The use of permanent magnets in this connection has advantages over using the springs 23, for in the case of a permanent magnet, when electromaget 22 retains the selector arm the attraction of the magnet 21 decreases in proportion as the selector arm moves away from the abutment 19 just the opposite of what occurs with the spring, so that the electromagnet 22 is required to develop a greater attractive force than when a permanent magnet is used. Since the spring is of use only when the selector arm 18 is required to remain in contact with the abutment 18, the extra pull developed by the spring in elongation is useless.

Clearly, therefore, the selector mechanism operates advantageously without using any spring a great advantage which enables very high selection rates to be achieved, inter alia because of the kinetic connection between the selector arms 18 and the needle bed 1, which ensures thorough synchronization. A rate of 100 selections/second/selector can be reached, and so the mechanism described with its ten selectors can provide 100 selections/second.

As well as operating rapidly, the selector mechanism described takes up little space and so can be provided in a large number around the needle bed. As an example, each ten-selector facility takes up only an angle of 2 30 around a 76 cm diameter needle bed. Power consumption is very reduced, being something like 0.04 watt/element, and the heat dissipation from all the selector devices causes only a very slight increase in the ambient temperature around the machine.

This selector system is simple to adjust and service and cheap to manufacture. As regards operation, the use of a sinusoidal cam is a means of reciprocating the slider in optimum conditions. The amplitude or the slider movement can be small, the selectors amplifying such movement.

What I claim and desire to secure by Letters Patent:

1. A knitting machine having a frame carrying a moving'support having a number of needles operable to two positions, an operative position and an inoperative position, a system for driving the support, means for individually moving the needle between their two positions,

, and a system for selecting such means characterized in that the selecting system comprises:

at least one moving selector arm having at one end a cam disposed near the support to act selectively on the needle-moving means;

a slider substantially perpendicular to the selector arm and which is pivoted thereto;

a cam having a substantially sinusoidal profile and which is solid in movement with the system for driving the support and which is in engagement with the slider to reciprocate the same between two positions, the cycle of such reciprocation corresponding to the consecutive passage past a fixed point of two needles controlled by the selector arm;

two abutments which are simultaneously adjacent the selector arm in one of its two end positions defined by the slider, and

means for continuously applying to the arm a first and predetermined force towards one of the abutments when the same makes contact with the selector arm, and means for selectively applying to the selector arm a second force which is greater than the first force and which is operative towards the outer of the abutments when the arm contacts such other abutment, so that the selector arm pivots while bearing on one or other of the abutments according as the second force is or is not applied,

causing the cam which is rigidly connected to the selector arm to make a movement proportional to the length of lever arm chosen.

2. A knitting machine according to claim 1, characterized in that said moving support is a rotating needle bed, the slider, which is disposed parallel to the needlebed axis, carrying a number of other selector arms which are disposed radially of the bed and which are articulated at various respective levels, and respective cams carried by the selector arms angularly offset from one another by an angle equal to the gauge of the machine.

3. A knitting machine according to claim 1, charac- 6 terized in that it comprises means for applying a force greater than and opposite to the first of said two forces in the limit pivoting position of the arm retained against the other of the abutments by the second force, so as to retain said arm in said pivoting position in the event of the power supply of the machine is interrupted.

4. In a knitting machine having a rotatably driven bed of knitting needles each operable to an operative knitting position and to a retracted, inoperative position, moving means releasably engaging the knitting needles for continuously reciprocably moving the knitting needles to said operative knitting position and the retracted, inoperative position thereof, the improvement which comprises a selector system for selectively, selecting individually which needles are to be disengaged from said moving means and for disengaging the selected needles individually from said moving means so that the disengaged selected needles remain on said bed inactive, said selector system comprising a plurality of pivoted selector arms each disposed to cooperate with a knitting needle to disengage it from said moving means, reciprocable means reciprocable relative the knitting needle bed pivotally mounting said selector arms, a plurality of electromagnets each associated with a corresponding selector arm and spaced from the pivot thereof energized selectively in accordance with a desired pattern attracting one end of the associated selector arm upon travel of said reciprocating means away from said electromagnets to one terminal position thereof to pivot it to a position effective to engage a corresponding knitting needle and disengage it from said moving means to render it inactive, and means on said moving means for re-engaging each disengaged needle after disengagement thereof to render it effec tive for knitting.

5. In a knitting machine, according to claim 4, in which said selector system reciprocable means comprises a slider driven reciprocably parallel to the axis of rotation of said knitting needle bed by said rotatably driven knitting needle bed, means on said slider and means on said knitting needle bed for reciprocably driving said slider from said knitting needle bed, means on said slider pivotally mounting the selector arms disposed offset angularly of the knitting needle bed an angle equal to the gauge of the machine, means holding the selector arms in a releasable position for rocking upon attraction by the electromagnet thereof to said position effective for disengaging its corresponding knitting needle from the moving means.

6. In a knitting machine according to claim 5, in which said knitting needle bed is circular in cross section and in which said selector arms are disposed radially of said knitting needle bed, and said selector arms are disposed spaced vertically on said slider.

'7. In a knitting machine according to claim 4, in which each electromagnet comprises a stationary abutment for a corresponding selector arm, and a plurality of second stationary abutments on a same side of each said selector arm when said reciprocating means is at another terminal position thereof, and means attracting one end of the individual said selector arms to said second abutments for releasably holding each selector arm against said abutment when said reciprocable means is at said another terminal position thereof. 

1. A knitting machine having a frame carrying a moving support having a number of needles operable to two positions, an operative position and an inoperative position, a system for driving the support, means for individually moving the needle between their two positions, and a system for selecting such means characterized in that the selecting system comprises: at least one moving selector arm having at one end a cam disposed near the support to act selectively on the needlemoving means; a slider substantially perpendicular to the selector arm and which is pivoted thereto; a cam having a substantially sinusoidal profile and which is solid in movement with the system for driving the support and which is in engagement with the slider to reciprocate the same between two positions, the cycle of such reciprocation corresponding to the consecutive passage past a fixed point of two needles controlled by the selector arm; two abutments which are simultaneously adjacent the selector arm in one of its two end positions defined by the slider, and means for continuously applying to the arm a first and predetermined force towards one of the abutments when the same makes contact with the selector arm, and means for selectively applying to the selector arm a second force which is greater than the first force and which is operative towards the outer of the abutments when the arm contacts such other abutment, so that the selector arm pivots while bearing on one or other of the abutments according as the second force is or is not applied, causing the cam which is rigidly connected to the selector arm to make a movement proportional to the length of lever arm chosen.
 2. A knitting machine according to claim 1, characterized in that said moving support is a rotating needle bed, the slider, which is disposed parallel to the needle-bed axis, carrying a number of other selector arms which are disposed radially of the bed and which are articulated at various respective levels, and respective cams carried by the selector arms angularly offset from one another by an angle equal to the gauge of the machine.
 3. A knitting machine according to claim 1, characterized in that it comprises means for applying a force greater than and opposite to the first of said two forces in the limit pivoting position of the arm retained against the other of the abutments by the second force, so as to retain said arm in said pivoting position in the event of the power supply of the machine is interrupted.
 4. In a knitting machine having a rotatably drIven bed of knitting needles each operable to an operative knitting position and to a retracted, inoperative position, moving means releasably engaging the knitting needles for continuously reciprocably moving the knitting needles to said operative knitting position and the retracted, inoperative position thereof, the improvement which comprises a selector system for selectively, selecting individually which needles are to be disengaged from said moving means and for disengaging the selected needles individually from said moving means so that the disengaged selected needles remain on said bed inactive, said selector system comprising a plurality of pivoted selector arms each disposed to cooperate with a knitting needle to disengage it from said moving means, reciprocable means reciprocable relative the knitting needle bed pivotally mounting said selector arms, a plurality of electromagnets each associated with a corresponding selector arm and spaced from the pivot thereof energized selectively in accordance with a desired pattern attracting one end of the associated selector arm upon travel of said reciprocating means away from said electromagnets to one terminal position thereof to pivot it to a position effective to engage a corresponding knitting needle and disengage it from said moving means to render it inactive, and means on said moving means for re-engaging each disengaged needle after disengagement thereof to render it effective for knitting.
 5. In a knitting machine, according to claim 4, in which said selector system reciprocable means comprises a slider driven reciprocably parallel to the axis of rotation of said knitting needle bed by said rotatably driven knitting needle bed, means on said slider and means on said knitting needle bed for reciprocably driving said slider from said knitting needle bed, means on said slider pivotally mounting the selector arms disposed offset angularly of the knitting needle bed an angle equal to the gauge of the machine, means holding the selector arms in a releasable position for rocking upon attraction by the electromagnet thereof to said position effective for disengaging its corresponding knitting needle from the moving means.
 6. In a knitting machine according to claim 5, in which said knitting needle bed is circular in cross section and in which said selector arms are disposed radially of said knitting needle bed, and said selector arms are disposed spaced vertically on said slider.
 7. In a knitting machine according to claim 4, in which each electromagnet comprises a stationary abutment for a corresponding selector arm, and a plurality of second stationary abutments on a same side of each said selector arm when said reciprocating means is at another terminal position thereof, and means attracting one end of the individual said selector arms to said second abutments for releasably holding each selector arm against said abutment when said reciprocable means is at said another terminal position thereof. 